Cycles of Time (book)
Encyclopedia
Cycles of Time: An Extraordinary New View of the Universe is a science book
by mathematical physicist Roger Penrose
published by The Bodley Head
in 2010. The book outlines Penrose's Conformal Cyclic Cosmology
(CCC) model, which is an extension of General Relativity
but opposed to the widely supported multidimensional string theories
and cosmological inflation following the Big Bang
.
of Thermodynamics and its inevitable march toward a maximum entropy
state of the universe
. Illustrating entropy in terms of information
state phase space
(with 1 dimension for every degree of freedom
) where particles end up moving through ever larger grains of this phase space from smaller grains over time due to random motion. He disagrees with Stephen Hawking's
back-track over whether information is destroyed
when matter enters black holes. Such information loss would non-trivially lower total entropy in the universe as the black holes whither away due to Hawking radiation
, resulting in a loss in phase space degrees of freedom.
Penrose goes on further to state that over incredibly long scales of time
(beyond 10100 years) distance ceases to be meaningful as all mass
breaks down into extremely red-shifted
photon
energy, where upon time has no influence, and the universe continues to expand without event
. This Big Bang to infinite expansion period represents an aeon
. The smooth “hairless” infinite oblivion of the previous aeon becomes the low entropy Big Bang state of the next aeon cycle. Conformal geometry
preserves the angles but not the distances of the previous aeon, allowing the new aeon universe to appear quite small at its inception as its phase space starts a new.
Penrose cites concentric rings found in the WMAP cosmic microwave background survey as preliminary evidence for his model as he predicted black hole collisions from the previous aeon would leave such structures due to ripples of gravitational waves.
and Doug Johnstone for The Scotsman
appreciate the against the grain innovative ideas Penrose puts forth. Manjit Kumar
reviewing for The Guardian
admires the Russian doll geometry play of the CCC concept, framing it as an idea of which M. C. Escher
"would have approved". Graham Storrs for the New York Journal of Books concedes that this is not the book that an unambitious lay person should plunge into.
Book
A book is a set or collection of written, printed, illustrated, or blank sheets, made of hot lava, paper, parchment, or other materials, usually fastened together to hinge at one side. A single sheet within a book is called a leaf or leaflet, and each side of a leaf is called a page...
by mathematical physicist Roger Penrose
Roger Penrose
Sir Roger Penrose OM FRS is an English mathematical physicist and Emeritus Rouse Ball Professor of Mathematics at the Mathematical Institute, University of Oxford and Emeritus Fellow of Wadham College...
published by The Bodley Head
The Bodley Head
The Bodley Head is an English publishing house, founded in 1887 and existing as an independent entity until the 1970s. The name has been used as an imprint of Random House Children's Books since 1987...
in 2010. The book outlines Penrose's Conformal Cyclic Cosmology
Conformal Cyclic Cosmology
The Conformal Cyclic Cosmology is a cosmological model in the framework of general relativity, advanced by the theoretical physicist Sir Roger Penrose. In CCC, the universe iterates through infinite cycles, with the future timelike infinity of each previous iteration being identified with the Big...
(CCC) model, which is an extension of General Relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
but opposed to the widely supported multidimensional string theories
String theory
String theory is an active research framework in particle physics that attempts to reconcile quantum mechanics and general relativity. It is a contender for a theory of everything , a manner of describing the known fundamental forces and matter in a mathematically complete system...
and cosmological inflation following the Big Bang
Big Bang
The Big Bang theory is the prevailing cosmological model that explains the early development of the Universe. According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the young Universe to cool and resulted in...
.
Part 1. The Second Law and its underlying mystery
- 1.1 The relentless march of randomness
- 1.2 Entropy, as state counting
- 1.3 Phase space, and Boltzmann's definition of entropy
- 1.4 The robustness of the entropy concept
- 1.5 The inexorable increase of entropy into the future
- 1.6 Why is the past different?
Part 2. The oddly special nature of the Big Bang
- 2.1 Our expanding universe
- 2.2 The ubiquitous microwave background
- 2.3 Space-time, null cones, metrics, conformal geometry
- 2.4 Black holes and space-time singularities
- 2.5 Conformal diagrams and conformal boundaries
- 2.6 Understanding the way the Big Bang was special
Part 3. Conformal cyclic cosmology
- 3.1 Connecting with infinity
- 3.2 The structure of CCC
- 3.3 Earlier pre-Big-Bang proposals
- 3.4 Squaring the Second Law
- 3.5 CCC and quantum gravity
- 3.6 Observational implications
- "Epilogue"
- "Appendices"
- "Notes"
- "Index"
Synopsis
Penrose examines implications of the Second LawSecond law of thermodynamics
The second law of thermodynamics is an expression of the tendency that over time, differences in temperature, pressure, and chemical potential equilibrate in an isolated physical system. From the state of thermodynamic equilibrium, the law deduced the principle of the increase of entropy and...
of Thermodynamics and its inevitable march toward a maximum entropy
Entropy
Entropy is a thermodynamic property that can be used to determine the energy available for useful work in a thermodynamic process, such as in energy conversion devices, engines, or machines. Such devices can only be driven by convertible energy, and have a theoretical maximum efficiency when...
state of the universe
Universe
The Universe is commonly defined as the totality of everything that exists, including all matter and energy, the planets, stars, galaxies, and the contents of intergalactic space. Definitions and usage vary and similar terms include the cosmos, the world and nature...
. Illustrating entropy in terms of information
Information
Information in its most restricted technical sense is a message or collection of messages that consists of an ordered sequence of symbols, or it is the meaning that can be interpreted from such a message or collection of messages. Information can be recorded or transmitted. It can be recorded as...
state phase space
Phase space
In mathematics and physics, a phase space, introduced by Willard Gibbs in 1901, is a space in which all possible states of a system are represented, with each possible state of the system corresponding to one unique point in the phase space...
(with 1 dimension for every degree of freedom
Degrees of freedom (physics and chemistry)
A degree of freedom is an independent physical parameter, often called a dimension, in the formal description of the state of a physical system...
) where particles end up moving through ever larger grains of this phase space from smaller grains over time due to random motion. He disagrees with Stephen Hawking's
Stephen Hawking
Stephen William Hawking, CH, CBE, FRS, FRSA is an English theoretical physicist and cosmologist, whose scientific books and public appearances have made him an academic celebrity...
back-track over whether information is destroyed
Black hole information paradox
The black hole information paradox results from the combination of quantum mechanics and general relativity. It suggests that physical information could disappear in a black hole, allowing many physical states to evolve into the same state...
when matter enters black holes. Such information loss would non-trivially lower total entropy in the universe as the black holes whither away due to Hawking radiation
Hawking radiation
Hawking radiation is a thermal radiation with a black body spectrum predicted to be emitted by black holes due to quantum effects. It is named after the physicist Stephen Hawking, who provided a theoretical argument for its existence in 1974, and sometimes also after the physicist Jacob Bekenstein...
, resulting in a loss in phase space degrees of freedom.
Penrose goes on further to state that over incredibly long scales of time
Time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
(beyond 10100 years) distance ceases to be meaningful as all mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
breaks down into extremely red-shifted
Red shift
-Science:* Redshift, the increase of wavelength of detected electromagnetic radiation with respect to the original wavelength of the emission* Red shift, an informal term for a bathochromic shift...
photon
Photon
In physics, a photon is an elementary particle, the quantum of the electromagnetic interaction and the basic unit of light and all other forms of electromagnetic radiation. It is also the force carrier for the electromagnetic force...
energy, where upon time has no influence, and the universe continues to expand without event
. This Big Bang to infinite expansion period represents an aeonAeon
The word aeon, also spelled eon or æon , originally means "life", and/or "being", though it then tended to mean "age", "forever" or "for eternity". It is a Latin transliteration from the koine Greek word , from the archaic . In Homer it typically refers to life or lifespan...
. The smooth “hairless” infinite oblivion of the previous aeon becomes the low entropy Big Bang state of the next aeon cycle. Conformal geometry
Conformal geometry
In mathematics, conformal geometry is the study of the set of angle-preserving transformations on a space. In two real dimensions, conformal geometry is precisely the geometry of Riemann surfaces...
preserves the angles but not the distances of the previous aeon, allowing the new aeon universe to appear quite small at its inception as its phase space starts a new.
Penrose cites concentric rings found in the WMAP cosmic microwave background survey as preliminary evidence for his model as he predicted black hole collisions from the previous aeon would leave such structures due to ripples of gravitational waves.
Reception
Most critics have found the book a challenge to fully comprehend, a few such as Kirkus reviewsKirkus Reviews
Kirkus Reviews is an American book review magazine founded in 1933 by Virginia Kirkus . Kirkus serves the book and literary trade sector, including libraries, publishers, literary and film agents, film and TV producers and booksellers. Kirkus Reviews is published on the first and 15th of each month...
and Doug Johnstone for The Scotsman
The Scotsman
The Scotsman is a British newspaper, published in Edinburgh.As of August 2011 it had an audited circulation of 38,423, down from about 100,000 in the 1980s....
appreciate the against the grain innovative ideas Penrose puts forth. Manjit Kumar
Quantum (book)
Quantum is a science history book written by Manjit Kumar. He describes Einstein, Bohr and the "Great Debate about the Nature of Reality" that played out over a number of years, particularly at the Fifth Solvay International Conference on Electrons and Photons in 1927...
reviewing for The Guardian
The Guardian
The Guardian, formerly known as The Manchester Guardian , is a British national daily newspaper in the Berliner format...
admires the Russian doll geometry play of the CCC concept, framing it as an idea of which M. C. Escher
M. C. Escher
Maurits Cornelis Escher , usually referred to as M. C. Escher , was a Dutch graphic artist. He is known for his often mathematically inspired woodcuts, lithographs, and mezzotints...
"would have approved". Graham Storrs for the New York Journal of Books concedes that this is not the book that an unambitious lay person should plunge into.